The invention relates to improvements in apparatus for conditioning fibrous materials, such as fragments of tobacco leaf laminae and/or fragments of tobacco ribs. More particularly, the invention relates to improvements in apparatus of the type wherein fibrous material which is to be puffed, moisturized, dried and/or otherwise conditioned is conveyed along an elongated path which is defined by a vibrating conveyor and wherein the fibrous material is conditioned as a result of contact with a hot fluid medium, particularly steam or a hot gaseous fluid (such as air).
Apparatus of the above outlined character, wherein the fibrous material is treated with steam are disclosed, for example, in published British patent application Ser. No. 21 38 666 and in U.S. Pat. No. 4,298,012 to Wochnowski (this patent was reissued under No. Re. No. 31,816). U.S. Pat. No. 3,877,469 to Wochnowski et al. discloses an apparatus wherein fibrous material is contacted by hot air. Published British patent application Ser. No. 20 75 373 discloses an apparatus wherein fibrous material is contacted with a liquid substance, such as water.
Heretofore known apparatus for the conditioning of tobacco and similar fibrous materials exhibit certain drawbacks, especially as concerns the exchange of heat and/or moisture between fibrous material and the fluid medium which is brought into contact with fibrous material, and also as concerns the deposition of undesirable substances in the conveyor wherein the fibrous material is treated by jets or streams of a hot, wet or dry fluid medium.